Mechanical Properties of Pillared-Graphene Nanostructures under Shear Loads
- PDF / 16,335,455 Bytes
- 7 Pages / 612 x 792 pts (letter) Page_size
- 41 Downloads / 252 Views
Mechanical Properties of Pillared-Graphene Nanostructures under Shear Loads H. Sasaki1, T. Hagi2, and K. Shintani1 1 Department of Mechanical Engineering and Intelligent Systems, University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan 2 Department of Human Media Systems, University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan ABSTRACT The shear deformations of pillared-graphene nanostructures are investigated using molecular dynamics simulation. Slight anisotropy regarding the direction of a shear load is detected. Changing the loading area in graphene and the radius of a single-walled carbon nanotube (SWNT) as a pillar, the deformations near the joints of graphene and a SWNT are examined in detail. It is concluded the anisotropy of the shear deformation of the nanostructure is due to the atomic structures at the joints of graphene and a SWNT as a pillar, and the out-of-plane deformations of graphene near the joints dominantly affect the overall shear deformation of the nanostructure. INTRODUCTION Recent researches of carbon nanomaterials such as carbon nanotubes and graphene deal with their physical properties and applications. One of their superior properties is the high thermal conductivity. It is the reason why carbon nanomaterials are applicable to materials to release heat in large-scale integrated (LSI) circuits. Transportations of thermal energy by carbon nanotubes and graphene are in one- and twodimensions, respectively, and lack the three-dimensionality. Kondo et al. [1] experimentally manufactured a carbon nanostructure named ‘pillared-graphene’. This nanostructure consists of two parallel graphene sheets and SWNTs; SWNTs connect the two graphene sheets as pillars whose axes are perpendicular to the plane of the graphene sheets (see figure 1). Since the thermal and electronic properties of pillared-graphene are superior, this nanostructure is expected to be applied to LSI circuits. Furthermore, vertically-connected pillared-graphene was also invented for the purpose of an application to enhanced hydrogen storage. Loh et al. [3] reported that the thermal boundary resistance, what is called the Kapitza resistance, of pillared-graphene varies under torsional and tensile loads. Therefore it is important to understand the mechanical behaviors of pillared-graphene under various loading conditions when its application is considered. Sihn et al. [4] performed a finite element analysis to estimate the effective elastic moduli of a pillared-graphene nanostructure. Their analytical frame work is based on the molecular mechanics approach where C-C bonds are modelled as beams of the equivalent elastic properties. In this paper, the deformation of a pillared-graphene nanostructure is investigated using molecular-dynamics simulation. The nanostructure model consists of two graphene sheets and a SWNT. A nanoscale force in the direction within the plane of the upper graphene sheet is imposed on a peripheral region of the sheet. On the other hand, a peripheral regio
Data Loading...
